Overview of the Kerr-McGee Chemical Corp –
Soda Springs Plant Superfund Site

Background and History

From 1964 to 1999, Kerr-McGee Chemical Corporation (Kerr-McGee) operated the Soda Springs plant that annually produced up to 4.5 million pounds of vanadium, an alloy used to manufacture steel. Vanadium was extracted from ferrous-phosphate ore purchased from the Monsanto plant next door.

The vanadium manufacturing process generated four waste streams—calcine tailings, roaster solids, phosphate minerals and extraction-derived raffinate—that were discharged into several lined and unlined ponds on the Site. From 1998 to 2000, Kerr-McGee also operated a plant that used calcine tailings to make fertilizer. Kerr-McGee demolished the vanadium and fertilizer plants in 2002 and 2003.

The unlined ponds storing vanadium-process waste leaked and contaminated groundwater and surface water. In 1989, contamination in groundwater led to the Site’s addition to the U.S. Environmental Protection Agency’s (EPA) National Priorities List of federal Superfund sites. In 1995, EPA issued a Record of Decision (ROD) that outlined EPA’s cleanup plan to prevent further leaching of contaminants into groundwater. The Site remedy that Kerr-McGee implemented between 1997 and 2001 included relocating contaminated sediments in the unlined ponds to an on-Site landfill, capping the calcine tailings, and long-term monitoring of groundwater quality.


The Multistate Trust’s Involvement

In the mid-2000s, Kerr-McGee transferred the Site to Tronox Incorporated (now Tronox Limited), a company newly formed by Kerr-McGee. Tronox filed for bankruptcy protection in 2009.

In 2011, as part of the Tronox bankruptcy settlement, the Multistate Environmental Response Trust (Multistate Trust) was created by a federal bankruptcy court to own, investigate, clean up, and facilitate the safe, beneficial reuse of the Site in Soda Springs, along with hundreds of other contaminated former Kerr-McGee/Tronox sites across the United States.

The Multistate Trust is a private, independent environmental response trust with the purpose of protecting human health and the environment. For more information, visit the Multistate Trust website.

In Soda Springs, the Multistate Trust performs its work under the oversight of EPA, as the Lead Agency for the Site, and in consultation with the Idaho Department of Environmental Quality (IDEQ).

The beneficiaries of the Multistate Trust include the United States, represented by EPA, and the State of Idaho, represented by IDEQ. Both EPA, in consultation with the U.S. Department of Justice (DOJ), and the State of Idaho must approve the sale, transfer, or disposition of all or any portion of the Site.

 Timeline of the Soda Springs Site

This timeline shows some of the key milestones and accomplishments achieved in the Site cleanup.

1963

Vanadium production facility began operations and continued until 1999.


1981

Unlined process ponds were found to be leaking liquid to groundwater.


1985

The State of Idaho Hazardous Materials Bureau conducted a Preliminary Assessment.


1988

EPA completed a Site Investigation.


1989

EPA added the Site to the National Priorities List.


1990

The Agency for Toxic Substances and Disease Registry completed a Preliminary Health Assessment.


1993

Kerr-McGee performed the Initial Risk Assessment.


1995

Kerr-McGee completed the Initial Remedial Investigation and Feasibility Study.

EPA issued the Record of Decision.


1997

Kerr-McGee finished the Remedial Design.


1997

EPA signed a Consent Decree with the potentially responsible party (Kerr-McGee).


2000

EPA issued the Record of Decision Amendment.


2001

Kerr-McGee completed construction of the remedy, including landfill construction and cap installation at the East Calcine Repository.


2005–2006

Kerr-McGee creates Tronox Incorporated (Tronox) and transfers hundreds of contaminated sites into Tronox without the funds needed for cleanup of the sites.


2009

Tronox filed for bankruptcy protection, mostly due to financial issues associated with Kerr-McGee’s past environmental liabilities.


2011

The Multistate Environmental Response Trust was established.


20142015

The Multistate Trust and Monsanto jointly conducted a domestic well survey and sampling program to ensure no residents use private wells for domestic water supply in areas of contaminated groundwater. The Multistate Trust also regularly samples the City water supply to ensure it’s not impacted by Site-related contamination.


20152016

Proceeds from a settlement of fraud claims against Kerr-McGee and related subsidiaries of Anadarko Petroleum Corporation (Anadarko litigation) provide additional Site funding.


20152019

The Multistate Trust conducted an extensive field investigation to identify Site-related chemicals, locate where they were released, evaluate where they have moved over time, and determine how they are continuing to move. This Supplemental Remedial Investigation (SRI) forms the basis for determining risks from Site-related chemicals and the best cleanup approaches.


2016

The Multistate Trust removed chemicals, wastes, and other materials abandoned on-Site by Tronox. In all, 910 tons of waste were relocated. A total of 565 tons of hazardous waste and 77 tons of nonhazardous waste were disposed, and 254 tons of metal and 14 tons of oil were recycled.


20172020

Human Health and Ecological Risk Assessments were conducted to determine risks due to Site-related contamination. No human health risks were identified from soil, surface water, sediment, fish consumption, or leaching to groundwater from surface soils. But potential human health risks exist from the assumed domestic use of groundwater on-Site and off-Site and the assumed industrial use of groundwater on-Site. The Ecological Risk Assessment recommended that monitoring continue, but concluded no additional action was warranted.


20182019

Waste materials buried throughout the Site had leached contamination into the ground and groundwater. More than 300,000 cubic yards of waste were excavated and placed in a waste repository on-Site. This cleanup action reduced the time needed to reach cleanup goals in some areas by approximately 50 years.


20182019

The Multistate Trust conducted various field investigation activities to support evaluation of remedial alternatives during the Focused Feasibility Study (FFS). Activities included chemical testing of soils, measurement of water flow below ground, and a pilot test to evaluate groundwater treatment.


20182019

Most Site buildings and utility infrastructure were demolished or decommissioned because of their poor condition and to facilitate investigation, cleanup and reuse. Seventeen buildings were demolished, one donated to the City, and two kept in place. Natural gas, water, and electrical supply lines to the Site were replaced. The Site was regraded to direct snowmelt and rainfall runoff away from former areas of contamination. These cleanup actions helped reduce the time to achieve Site cleanup and have promoted future productive Site reuse.


20182019

A lined repository, equipped with leachate collection, was constructed on-Site to hold waste from a 10-acre waste-storage pond, waste excavation, and facility demolition.


2018

Approximately 1.5 million gallons of hazardous liquid were removed from a 10-acre pond on-Site. The pond itself was eliminated to prevent leakage through a weakening pond liner, eliminating a significant contamination risk.


20212022

Using the SRI, risk assessments, and FFS field data collection, the FFS Report evaluated remedial alternatives to help select the most appropriate additional cleanup action to be taken. The Draft FFS Report was completed in 2021, and EPA approved the Final FFS Report Revision 2 in December 2022.


A Proposed Plan for changes to the Site cleanup approach was issued in March, based on alternatives evaluated in the FFS Report. A public meeting and comment period took place. In November, EPA issued the Record of Decision Amendment, to select a revised remedy to address soil and groundwater contamination.

2023


Funds for the Soda Springs Site

Cleanup funds were provided by the companies responsible for Site contamination—not by the U.S. government or by tax dollars. Funding came from the Tronox bankruptcy settlement and included proceeds from a settlement of fraud claims against Kerr-McGee and related subsidiaries of Anadarko Petroleum Corporation (Anadarko litigation).

In 2011, when the Multistate Trust was created, initial funding was provided to maintain basic Site activities.

The receipt of additional funds from the Anadarko litigation in 2015 and 2016 allowed the Multistate Trust to begin proactively conducting Site investigations to plan and implement remedial actions at the Site under EPA oversight.

The Multistate Trust can use Site-specific funds only for environmental actions, such as Site investigations, studies, designs, cleanup actions, operations, and maintenance.

Site-specific funds cannot be used for other purposes, including the actual redevelopment of the Site, or compensating people for health effects or property damage associated with the Site. 


Tronox Tort Claims Trust

THE TRONOX TORT CLAIMS TRUST IS NOT PART OF THE INVESTIGATION, REMEDIATION, AND REDEVELOPMENT PLANNING OF THE SITE.

As a result of the Tronox bankruptcy proceedings, the Multistate Trust was created to perform investigation, cleanup, and redevelopment planning activities at the Site in Soda Springs.

A separate Trust – the Tronox Tort Claims Trust – was established to pay personal injury claims (medical or health) and property damage claims associated with Kerr-McGee’s prior operations.

Visit the Tronox Tort Claims Trust website or contact the Tronox Tort Claims Trust by email at tronoxtorttrust@epiqglobal.com or phone at (800) 753-2480.

The Multistate Trust cannot pay personal injury or property damage claims.

The Multistate Trust and EPA have no involvement in the Tronox Tort Claims Trust.